Carrier arrangements are basically already known from DE 101 29 418 A1. This publication discloses a laminated carrier comprising a first end plate, a second end plate and a connection, the first and second end plates being connected to each other so that windows are formed between said plates for the arrangement of planet gears. At least one of the first and the second plates comprises a plurality of material layers that are connected to one another such that a non-uniform internal structure is formed. The carrier arrangement shown in DE 101 29 418 A1 comprises planet gears that are mounted through planet shafts.
A further carrier arrangement known from DE10203880 A1 is made up of two carrier parts, planet gears and webs. The planet gears are arranged between the carrier parts. The webs connect the carrier parts to each other. For this purpose, the ends of the webs are inserted and calked into apertures of the carrier parts.
However, planet gear carrier plates are also known that transfer torques to the planet gears that are mounted via the tip circle, i.e., as “centerless” or loose planet gears on the planet gear carrier plate.
Thus, WO 2009/013065 A2 discloses a planetary differential transmission comprising a driving spur gear comprising an outer gearing and, connected rotationally fast to this, a planet gear carrier arranged in the hub region of the driving spur gear. Said planet gear carrier carries at least one pair of meshing planet gearwheels, each of the at least two planet gearwheels being in meshing engagement with a respective sun gear that is connected rotationally fast to a driven shaft and comprises an outer gearing. The planetary differential transmission includes at least one heterodyne step that comprises at least one idler pinion that is in meshing engagement with one of the driven shafts and in meshing engagement with an annulus that is coupled rotationally fast to the driving spur gear. The at least one heterodyne step further comprises at least one controllable clutch for a variable deceleration of the at least one idler pinion relative to a housing section and/or relative to the at least one driven shaft, or comprises a controllable clutch for a variable deceleration or acceleration of the annulus relative to the driving spur gear.
DE 1 650 737 further discloses self-locking differential transmissions comprising spur gears. In the self-locking differential transmissions comprising spur gears disclosed in this document, a number of first planet gears are arranged in a first planet orbit and mesh with one of the two sun gears, and a number of second planet gears are arranged in a second planet orbit and mesh with the other of the two sun gears, one of the first planet gears meshes with at least one of the second planet gears, and all planet gears are supported through a friction mounting in the planet gear carrier through their tooth heads, at least one spring ring exerting an all-around radial compressive force on the planet gears for obtaining an additional radial force between the planet gears and their mounting surfaces in the planet gear carrier.
A differential arrangement is also known from U.S. Pat. No. 3,738,192. In this arrangement, individual planet gears are loosely mounted between two plates within a spur gear and are alternatingly in meshing engagement with each other.
However, the existing and known planet gear carriers generally have the drawback that they are particularly heavy.
A planet carrier that is made up of two carrier parts, webs between the carrier parts and planet gears between the webs is shown in U.S. 2003/0181284 A1. Both the carrier parts as well as the webs that connect the carrier parts to each other have a solid structure.
Efforts have been made to improve this situation by providing apertures so that light weight planet gear carriers are created. However, such light weight planet gear carriers have the drawback of not being particularly stable or torsion resistant under extreme types of loading.
A known solution that is supposed to eliminate this drawback is described in DE 44 21 931 A1. DE 44 21 931 A1 describes a planet gear carrier made up of two carrier parts. The carrier parts are connected to each other through axially oriented webs that extend between mounting regions for the planet gears. As a stiffening element for the planet carrier, the webs have such a solid configuration that they fully occupy the maximum empty space available between the planets. One of the carrier parts comprises apertures into each of which one of the webs is inserted with an interference fit with the result that the apertures which otherwise weaken the carrier part are filled by the stiffening element.